Experimental study of oversized grafts in a canine living-donor lobar lung transplantation model

BACKGROUND: For infants and small children, organ transplantation is limited by the size discrepancy between donor and recipient. To address this problem, the use of over-sized grafts from living-relative donors could potentially expand the donor pool. The aim of this experimental study was to evaluate the effect of oversized grafts on early pulmonary function and to identify an indicator for acceptable size discrepancy. METHODS: Fourteen bilateral lobar lung allotransplant operations were performed without cardiopulmonary bypass in weight mismatched pairs of dogs. Animals were divided into 2 groups: Group I (n = 7), donor/recipient lung volume ratio < 2.85; Group II (n = 7), donor/recipient lung volume ratio >2.85. Pulmonary function of the recipient was measured before chest closure, after chest closure, and after the ventilator was removed. RESULTS: Pulmonary vascular resistance and airway pressure significantly increased in Group II after chest closure (1493 +/- 195 dynes sec cm(-5) and 14.4 +/- 0.9 mm Hg vs 2784 +/- 140 dynes sec cm(-5) and 23.4 +/- 1.2 mm Hg, p < 0.001). After the ventilator was removed, all recipients in Group I showed PaO2 > 239 mm Hg and PaCO2 < 76 mm Hg, whereas, all recipients in Group II showed PaO2 < 116 mm Hg and PaCO2 > 169 mm Hg. The donor/recipient chest circumference ratio was less than 1.3 in all but 1 dog in Group I. CONCLUSIONS: Acceptable, oversized grafts provide adequate pulmonary function, although excessively oversized grafts cause significant impairment in pulmonary function after chest closure. Chest circumference provides useful size-match criteria when oversized grafts are used in this canine experimental model.     

Effects of inhaled nitric oxide in a canine living-donor lobar lung transplant model.

OBJECTIVE: In living-donor lobar lung transplantation, early severe graft dysfunction can occur if the size or amount of transplanted lung tissue is insufficient. The purpose of this study was to evaluate the effects of inhaled nitric oxide on early pulmonary function in a canine bilateral living-donor lobar lung transplant model. METHODS: Sixteen pairs of mongrel dogs with a donor/recipient weight ratio less than 1.2 were used. The donor lung bloc was extirpated after heparinization. Right middle, lower and cardiac lobes were implanted as a right lung of the recipient and left lower lobe was implanted as a left lung without cardiopulmonary bypass. In Group 1 (n = 9), nitric oxide gas was administered continuously at a concentration of 40 parts per million prior to reperfusion of the right lung throughout the 6-hour assessment period after transplantation. In Group 2 (n = 7), nitrogen gas was administered in the same manner as nitric oxide, for control. RESULTS: At the end of assessment, the survival rate was 89% (8/9) in Group 1 and 57% (4/7) in Group 2. The arterial oxygen tension in Group 1 was significantly higher than that in Group 2. The pulmonary arterial pressure and pulmonary vascular resistance index were significantly lower in Group 1 than in Group 2. The aortic pressure and cardiac index did not differ significantly between the two groups. The wet-to-dry weight ratio and myeloperoxidase activity were significantly lower in Group 1 than in Group 2. CONCLUSIONS: These data suggested that inhaled nitric oxide improved early pulmonary function in living-donor lobar lung transplantation by vasodilatating the pulmonary vasculature and inhibiting neutrophil activation.     

Suppressed erythropoiesis after ABO-minor-mismatched living-donor lobar lung transplantation.

Anti-A and/or anti-B antibodies synthesized by lymphoid tissues contained in ABO-mismatched solid organ grafts have been reported to cause hemolytic anemia, but not suppressed red blood cell production. A case of living-donor lobar lung transplantation is presented in which suppression of erythropoiesis was associated with ABO mismatched organ transplantation.     

First successful bilateral living-donor lobar lung transplantation in Japan

No successful lung transplantation has been reported in Japan until recently when we performed the first successful bilateral living-donor lobar lung transplantation. A 24-year-old woman with primary ciliary dyskinesia began experiencing severe respiratory insufficiency and required mechanical ventilation. On October 28, 1998, she underwent bilateral living-donor lobar transplantation, receiving her sister's lower right lobe and her mother's left lower lobe under cardiopulmonary bypass. The patient was discharged from the hospital 61 days after transplantation. Six months postoperatively, she has returned to normal life and is able to carry out daily activities. She is in good physical condition with a vital capacity of 1.77 L.     

The technique of unilateral double lobar lung transplantation in a canine model

OBJECTIVE: Bilateral living-donor lobar lung transplantation has become an accepted alternative to cadaveric lung transplantation. Because only one lobe is implanted in each chest cavity, this procedure seems to be best suited for children and small adults. The purpose of this study was to develop a technique of unilateral double lobar lung transplantation that can be applied to large adult patients. METHODS: Unilateral double lobar lung transplantation was performed in 6 weight-matched pairs of dogs. In donor animals the right middle, lower, and cardiac lobes were separated as a right graft, and the left lower lobe was separated as a left graft. In recipient animals these 2 grafts were implanted in the right hemithorax after right pneumonectomy. The left graft was implanted as a right upper lobe, having been rotated 180 degrees along the vertical axis and then 180 degrees along the horizontal axis. The right graft was implanted in the natural anatomic position. Function of the transplanted grafts was assessed for 3 hours after ligation of the left main pulmonary artery while the animals were ventilated with 100% oxygen. RESULTS: Morphologic adaptation of the 2 grafts in the right hemithorax was found to be excellent. All 6 animals survived the assessment period with excellent pulmonary function. At the end of the 3-hour assessment period, the arterial oxygen tension was 519 +/- 31 mm Hg, and the mean pulmonary artery pressure was 30.5 +/- 1.7 mm Hg. CONCLUSIONS: Unilateral double lobar lung transplantation was technically possible and associated with satisfactory early pulmonary function in a canine experimental model.     

Outcomes of various transplant procedures (single,sparing, inverted) in living-donor lobar lung transplantation

Objectives

In standard living-donor lobar lung transplantation (LDLLT), the right and left lower lobes from 2 healthy donors are implanted. Because of the difficulty encountered in finding 2 donors with ideal size matching, various transplant procedures have been developed in our institution. The purpose of this retrospective study was to compare outcomes of nonstandard LDLLT with standard LDLLT.

Favorable outcomes after living-donor lobar lung transplantation in ventilator-dependent patients

Purpose  Living-donor lobar lung transplantation (LDLLT) is performed in critically ill patients, although the outcome is generally expected to be poor for those who are ventilator dependent. The aim of this study was to compare the outcomes of LDLLT in ventilator-dependent patients compared with those in ventilator-independent patients. Methods  We reviewed 31 consecutive patients who received LDLLT between October 1998 and May 2004. Results  Five patients were ventilator dependent and 26 were ventilator independent. All five ventilator-dependent patients were female, with a mean age of 29.6 years. The duration of preoperative ventilation was 23.4 ± 5.7 days. The underlying diagnoses in the ventilator-dependent patients included only obstructive (n = 3) and infectious lung diseases (n = 2), whereas those in the ventilator-independent patients included hypertensive and restrictive diseases (P = 0.004). There were no significant differences between the groups in early postoperative clinical values. The incidences of acute rejection and bronchiolitis obliterans syndrome (BOS) were comparable. The 5-year survival rates were 100% for the ventilator-dependent patients and 92.3% for the ventilator-independent patients (P = 0.45). Conclusion  Our findings suggest that LDLLT can have a favorable outcome in selected ventilator-dependent patients.     

Referrals for lung transplantation in Japan. Unique indications and necessity of living-donor lobar lung transplantation.

OBJECTIVES: The purpose of this study was to review all referrals to our lung transplant program and to find realistic options for accepted candidates in Japan. METHODS: During the period from April 1992 to August 1999, 45 referrals were received. After screening, 22 of the referred patients were admitted for an extensive inpatient evaluation, and 15 of these were accepted as candidates for transplantation. RESULTS: The indication was primary pulmonary hypertension in 9, bronchiectasis in 2, lymphangioleiomyomatosis in 2, idiopathic pulmonary fibrosis in 1, and pneumoconiosis in the other 1. Two of those with primary pulmonary hypertension went to the USA and there received bilateral lung transplant. One with bronchiectasis received living-donor lobar lung transplantation in our center. These three recipients are alive and doing well during the follow-up period of 11 to 69 months. Among the 12 patients who have not received lung transplant, 5 patients have died while waiting. CONCLUSIONS: Indications for lung transplant are quite distinct in Japan, and primary pulmonary hypertension is the most frequent indication. Living-donor lobar lung transplantation is a realistic option for properly selected candidates.     

One year follow-up of the first bilateral living-donor lobar lung transplantation in Japan.

One-year follow-up results on Japan's first bilateral living-donor lobar lung transplantation concern a 24-year-old woman who had become ventilator-dependent due to severe bronchiectasis associated with primary ciliary dyskinesia. Surgery was conducted using her sister's right lower lobe and her mother's left lower lobe. Total forced vital capacity of the 2 transplanted lobes was 51.7% of the recipient's predicted forced vital capacity. One-year after transplantation, her forced vital capacity was 2,160 ml--73.2% of her predicted forced vital capacity. The recipient's sister's decrease in forced vital capacity was 410 ml and that of her mother 440 ml. The recipient and donors have since returned to normal, unrestricted lives.     

Comparison of canine single and sequential bilateral lung transplant model for lung preservation study

The purpose of this study was to compare canine sequential bilateral lung transplantation (SBLT) with left single lung transplant (LSLT) models. After 24 hours of lung preservation with low potassium/dextran glucose (LPDG) solution, seven SBLT procedures were performed using mongrel dogs. The comparative group including nine cases of LSLT. After completion of each transplant, the dogs were maintained on a ventilator for 3 hours. Thereafter serial hemodynamics were evaluated with recipients with chest X-ray, computed tomography, and lung perfusion scan checked at 2 hours after transplantation. Pathological evaluations were also performed. Five of seven SBLT successfully completed the whole assessment, all LSLT survived. In SBLT, pulmonary arterial pressure and pulmonary vascular resistance were significantly elevated, but recovered 3 hours after reperfusion. The ultrastructural aspects of alveolae and pulmonary artery endothelium showed a reversible mild injury 24 hours after lung preservation and reperfusion. The present study suggests that the canine SBLT model using LPDG solution provides an excellent preservation effect and is more physiological as the dog is completely dependent on the function of the transplanted lung.     

Antibody-mediated rejection of a unilateral donor lung in bilateral living-donor lobar lung transplantation: report of a case

We report a case of antibody-mediated rejection (AMR) of a unilateral donor lung in the presence of newly formed donor-specific antibodies, 10 months after living-donor lobar lung transplantation (LDLLT). Of note is that the AMR occurred in the unilateral lung. Furthermore, the lung graft was from her husband and HLA analysis on the recipient's daughter revealed the same donor-specific HLA antigens, which strongly suggested pre-sensitization before lung transplantation. Fortunately, we could perform direct crossmatch even 1 year after lung transplantation because of the living donors.     

Immediate single lobar retransplantation for primary graft dysfunction after living-donor lobar lung transplantation: Report of a case

A 24-year-old man with cystic fibrosis underwent living-donor lobar lung transplantation (LDLLT) with grafts donated from his father, who had mild cirrhosis, and his uncle. The graft from his father failed, and retransplantation was required 44 h after LDLLT, using his sister's left lower lobe. The retransplantation was successful; 18 months postoperatively, the recipient and all three donors are doing well. The favorable outcome was achieved owing to the complete assessment of all potential donors in advance, and the appropriate decision to perform retransplantation in a timely manner. Whether this life-saving retransplant procedure for unexpected primary graft dysfunction after LDLLT can be justified requires further experience and a longer follow-up.     

Inhaled nitric oxide ameliorates postoperative acute graft dysfunction after living-donor lobar lung transplantation.

Inhaled nitric oxide, a selective pulmonary vasodilator, decreases mean pulmonary artery pressure and pulmonary vascular resistance and improves oxygenation in previously unobtainable ways without significant changes in systemic hemodynamics. We report successful treatment of a patient with acute graft dysfunction after living-donor lobar lung transplantation using nitric oxide inhalation.     

Anastomosis of an anomalous segmental vein with the azygos vein in living-donor lobar lung transplantation.

We report the case of a living-donor lobar lung transplantation in which we found an abnormal segmental vein in the right lower lobe of the donor lung. The abnormal vein was anastomosed to the azygos vein of the recipient so that lung edema and congestion could be avoided. This alternative technique is effective in living-donor lobar lung transplantation when the superior segmental vein in the right lower lobe of the donor drains into the superior vein.     

Equivalence of flow velocities through bilateral pulmonary vein anastomoses in bilateral living-donor lobar lung transplantation.

BACKGROUND: Intraoperative transesophageal echocardiography (TEE) during lung transplantation is useful for monitoring cardiac condition and pulmonary vascular anastomoses to detect vascular complications, but the parameters for evaluation by TEE during lung transplantation have not been established. METHODS: We performed intraoperative TEE on 17 patients during living-donor lobar lung transplantation (LDLLT) and investigated the usefulness of measurement of peak flow velocities through bilateral pulmonary vein (PV) anastomoses and evaluation of the equivalence. RESULTS: The peak flow velocities through bilateral PV anastomoses were almost equivalent in 14 patients without complications and were not equivalent in 3 patients with complications such as vascular stenosis and peripheral atelectasis. CONCLUSIONS: The flow velocities through the bilateral PV anastomoses are shown to be nearly equivalent during bilateral LDLLT, and the equivalence may be one factor for predicting the success of LDLLT.